Analog Devices Inc./Maxim Integrated MAX38904AATD+T

Overview

MAX38904AATD+T from Analog Devices is a 2A, low-noise linear regulator in a 3mm × 3mm 14-pin TDFN package, delivering ±1% output accuracy over load, line, and temperature with only 47mV dropout at full load and 5.1μVRMS output noise (10Hz–100kHz). It features pin-selectable fixed outputs (1.2V–5.0V), active discharge (70Ω), and operates from 1.7V to 5.5V input - ideal for powering high-resolution ADCs and precision analog front-ends in medical instrumentation.

For engineers reviewing the MAX38904AATD+T datasheet, MAX38904AATD+T pinout, MAX38904AATD+T application, or MAX38904AATD+T equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters, and real-world application mappings - all specific to the MAX38904AATD+T variant with SELA/SELB voltage selection and TDFN packaging.

Technical Context

The MAX38904AATD+T implements a PMOS-based LDO architecture with internal 0.6V reference and precision error amplifier, enabling stable regulation across wide input/output differentials. Its pin-selectable output logic reads SELA and SELB states at power-up to configure one of nine factory-trimmed voltages without external resistors.

It integrates active discharge (70Ω pull-down on OUT when disabled), programmable soft-start via BYP capacitor, and protection against overcurrent, thermal overload, and reverse current - all while maintaining <1.3mA quiescent current independent of dropout voltage.

Key Specifications

Pinout & Package

MAX38904AATD+T uses a 3mm × 3mm, 14-pin TDFN package with exposed pad (EP) for thermal dissipation. Pin layout is optimized for low-inductance IN/OUT/GND routing and minimal loop area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TSM1052-3.3TR and TPS7A8300RGRT, the MAX38904AATD+T uniquely combines pin-selectable fixed outputs, 47mV dropout, and 5.1μVRMS noise in a 3mm × 3mm TDFN - making it optimal for space-constrained, multi-rail, high-precision analog systems requiring zero-resistor configuration and fast discharge.

Availability

MAX38904AATD+T is available at Aetrix Electronics and suitable for medical imaging signal chains, high-end audio DAC power, test & measurement instrumentation, and industrial data acquisition modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX38904AATD+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision, industrial, communications, and automotive markets since 1965.

The MAX38904 family is designed for ultra-low-noise, high-accuracy power regulation in sensitive analog systems - targeting applications where PSRR, output noise, and dropout voltage directly impact measurement fidelity and signal integrity.

FAQ

What output voltages does the MAX38904AATD+T support?

The MAX38904AATD+T supports nine pin-selectable fixed outputs: 1.2V, 1.5V, 1.8V, 2.5V, 3.0V, 3.1V, 3.3V, 4.0V, and 5.0V. Selection is determined by the logic states (Hi-Z, GND, or IN) applied to SELA and SELB pins at power-up - no external resistors required. Each combination maps to a specific voltage per the device's configuration table.

Does the MAX38904AATD+T include active discharge functionality?

Yes, the MAX38904AATD+T includes a 70Ω active discharge circuit between OUT and GND that engages automatically when EN is pulled low. This rapidly discharges output capacitors - reducing discharge time for a 22μF cap to under 1.6ms - which simplifies power sequencing in multi-rail systems and prevents back-powering of upstream circuitry.

What is the minimum output capacitance required for stability with the MAX38904AATD+T?

The MAX38904AATD+T requires a minimum of 8μF ceramic output capacitance (X5R or X7R dielectric) for stable operation. This value accounts for voltage and temperature derating - actual installed capacitance must remain ≥8μF across the full -40°C to +125°C range and rated output voltage. A 22μF capacitor is recommended for optimal transient response.

How does the BYP pin function in the MAX38904AATD+T?

The BYP pin on the MAX38904AATD+T connects to OUT via a capacitor (1nF–100nF) to filter reference noise and control soft-start slew rate. A 47nF capacitor yields ~5V/ms startup, limiting inrush current to ~110mA when charging a 22μF output cap. BYP also serves as a high-speed feedback path to improve load transient response.

What thermal considerations apply to the MAX38904AATD+T in its TDFN package?

The MAX38904AATD+T in the 3mm × 3mm TDFN package relies on its exposed pad (EP) for thermal conduction. For θJA ≤ 41°C/W, EP must be soldered to a solid PCB ground plane with ≥4 thermal vias (0.3mm diameter, spaced ≤1mm apart). Without proper thermal design, junction temperature may exceed 150°C under 2A load at +70°C ambient.